SGC SG-2000 - Page 203

SG-2000 MANUAL 196
The SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
©1995, SGC, Inc. TEL: (206) 746-6310 FAX: (206) 746-6384
23.4.8 Reference Logic
IC2 is a 5 volt regulator, 78L05.
IC3 is a Dual 2-to-4 Line Decoder, 74HC139.
Truth Table
IC3A
G
P1
H
L
L
L
L
A4
P2
X
L
H
L
H
A5
P3
X
L
L
H
H
Y3
P7
H
H
H
H
L
Outputs
Inputs
Truth Table
IC3B
G
P15
H
L
L
L
L
A6
P14
X
L
H
L
H
A7
P13
X
L
L
H
H
Y2
P10
H
H
H
L
H
Y3
P9
H
H
H
H
L
Outputs
Inputs
IC4 is a Quad 2-Input NAND Gate, 74HC00.
Truth Table
IC4C
A2
P10
L
L
H
H
A3
P9
L
H
L
H
P8
H
H
H
L
Outputs
Inputs
H = high
L = low
IC5 is a Triple 3-Input NOR Gate, 74HC27.
Truth Table
IC5B
A2
P3
L
X
X
H
A3
P4
L
X
H
X
UCE
P6
H
L
L
L
Outputs
Inputs
H = high
L = low
X = don't care
Y3
P5
L
H
X
X